Drilling apparatus



July 13, 1943. F. H. MUELLER ETAL 2,324,225

DRILLING APPARATUS Original Filed July 17, 1940 HQ I 13 m 7 1.5

? L.. H L

Vl aZterJ Eowan.

Patented July 13, 1943 UNITED STATES PATENT QFFICE Ill., assignors to Mueller 00., Decatur, 111., a corporation of Illinois Original application July 17, 1940, Serial No.

346,052. Divided and this application December 12, 1941, Serial No. 422,772

1 Claim.

This invention relates to drilling machines of the type used in drilling mains containing pressure fluid. Such machines comprise a barrel disposable in sealed radial relation to a main and a removable cap closing and sealing against the outer end of the barrel, the cap having a bore in which is rotatable and reciprocable the boring bar which carries the drilling tool. In order to prevent leakage between the cap bore and the bar it is necessary to provide packing means between the two. This packing means is subject to severe wear as the result of the rotation and reciprocation of the bar in the use of the machine and ordinarily soon becomes ineiiective and must be replaced. The object of the present invention is to provide means for tightening or constricting the packing to compensate for wear and thereby extend its useful life, and to dispose the packing accessibly and in a manner enabling the length of the barrel to be substantially reduced. How this object may be attained is illustrated in the accompanying drawing wherein:

Figure 1 is a partial axial section of a drilling machine barrel, cap and boring bar, the cap being equipped in accordance with the invention.

Figure 2 is a section on line 22 of Figure 1, and

Figure 3 is a section similar to that of Figure 2 of another embodiment of the invention.

Referring first to Figures 1 and 2, the refer ence numeral Ii] designates the upper portion of the barrel and reference numeral H the cap. The cap includes a depending annular skirt Ha provided with means for disengageably engaging the barrel, here shown as threads. The top includes a neck portion llb projecting oppositely from the skirt coaxially with the latter and the top has a bore [3 which extends through the neck coaxially with the skirt.

A boring bar 14 is rotatable and slidable in the bore and has a lower end enlargement Ma which in the uppermost position of the bar directly abuts the undersuriace of the cap substantially on a level with the top of the inner wall of the skirt within an annular gasket 12 which is interposed between the undersurface of the cap and the top of the barrel.

Formed in the neck H1) is an annular groove 15 which surrounds the boring bar and is intersected by a threaded bore [6 whose axis, as here shown, is in a plane normal to the axis of bore l3. Bore I6 is substantially tangential to bore 13 and to the boring bar, although spaced somewhat away from strict tangency, and where the bore l6 enters the groove l5 an enlargement ll 55 of the latter occurs. The groove, including its enlargement, is filled with suitable packing material P, which, with the boring bar in the bore I3, may be stuffed in through the bore 16. However, the packing might be preformed and inserted in the groove prior to the assembly of the boring bar with the cap. In any event, with the packing material positioned in and filling the groove IS, a screw l8 may be advanced in the bore I6 to engage and compress the packing, and as wear occurs in the use of the machine this screw may be commensurately advanced to compress the packing so as to maintain its original effectiveness. When the screw can no longer be advanced it may be removed, further packing introduced through bore l6, and the screw replaced. Thus by adding packing material when necessary it need never be necessary to replace the packing as a whole.

In drilling machines as heretofore designed,

there has been provided a packing including a gland nut which projects inwardly from the undersurface of the cap and the boring bar can only be pulled into the barrel until its end enlargement abuts the nut. Furthermore, the gland nut is only accessible for adjustment when the cap is removed. According to the present invention, the inwardly projecting gland nut is eliminated and the packing is arranged for adjustment from the top of the cap, being thus always accessible. The enlargement on the boring bar abuts the undersurface of the cap substantially on a level with the top of the inner wall of the cap skirt when the boring bar is in its uppermost position. Therefore, retaining the usual reciprocating range of the boring bar, the present invention enables the length of the barrel to be made considerably less than usual, rendering the machine that much more adaptable for use in close quarters.

For greater convenience in the introduction of the packing material, the form of the invention shown in Figure 3 may be used. According to the embodiment shown in this figure, a counterbore l9 of considerably larger diameter than the counterbore [6 of Figures 1 and 2 is provided in the cap H and threaded therein is a nipple 20 having internal threads engaged by the screw 18. The packing material P can be readily stufied into place through the large opening i9 and then the nipple and screw threaded in. In this form the groove 15' has a more pronounced enlargement l 1'.

It will be evident that by positioning the screw l8 substantially tangentially to the bar a much greater range of adjustment is possible than as though it were arranged radially or in any other relation wherein it would be directed toward the bar.

Variations are, of course, possible in the described arrangement and accordingly we do not limit ourselves to the specific showing herein except as in the claims.

This application is a division of our application Serial No. 346,052, filed July 17, 1940, which has matured into Patent No. 2,291,979 on Aug. 4, 1942.

We claim:

In a drilling machine, a barrel cap having a sitely from the skirt coaxially with the latter, said top having a bore extending through said neck coaxially with the skirt, a boring bar rotatable and slidable in said bore and having a lower end enlargement which in the uppermost position of the bar directly abuts the undersurface of the cap substantially on a level with the top of the inner Wall of the skirt, said neck having an annular groove therein surrounding said bar, packing material in said groove, said neck being provided with a bore intersecting said groove substantially tangentially to said bar, and a member in the last-named bore accessible from the upper side of the top to be forced into the top and a depending annular skirt provided with 15 packing material to compress the same.

means for disengageably engaging a barrel, said top including a neck portion projecting oppo- FRANK H. MUELLER. WALTER J. BOWAN. 

